fix(igxCombo): Prevent toggle on click of disabled combo.

Author: MKirova

projects/igniteui-angular/src/lib/combo/combo.component.spec.ts

@@ -2439,6 +2439,13 @@ describe('igxCombo', () => {
                 expect(combo.valid).toEqual(IgxComboState.INITIAL);
                 expect(combo.comboInput.valid).toEqual(IgxInputState.INITIAL);
             });
+            it('should not open on click if combo is disabled', () => {
+                combo.disabled = true;
+                fixture.detectChanges();
+                UIInteractions.simulateClickEvent(combo.comboInput.nativeElement);
+                fixture.detectChanges();
+                expect(combo.dropdown.collapsed).toBeTruthy();
+            });
             it('should be possible to be enabled/disabled when used as a form control', () => {
                 const form = fixture.componentInstance.reactiveForm;
                 const comboFormReference = form.controls.townCombo;

projects/igniteui-angular/src/lib/combo/combo.component.ts

@@ -867,7 +867,9 @@ export class IgxComboComponent extends DisplayDensityBase implements IgxComboBas
     onInputClick(event: Event) {
         event.stopPropagation();
         event.preventDefault();
-        this.toggle();
+        if (!this.disabled) {
+            this.toggle();
+        }
     }
 
     /**